1. Field of the Invention
The present invention relates to a supporting wall structure for receiving a thrust force of a planetary gear mechanism constituting a forward and backward change-over mechanism in a toroidal type infinitely variable automatic transmission.
2. Description of the Prior Art
In a toroidal type infinitely variable automatic transmission, because a toroidal transmission mechanism is moved in the axial direction and still the control of the axial force of the toroidal transmission mechanism is difficult, it is necessary to prevent the axial thrust force generated in a forward and backward change-over mechanism adjacent to the toroidal transmission mechanism from being transmitted to the toroidal transmission mechanism.
A supporting wall for receiving this thrust force is provided between the forward and backward change-over mechanism and the toroidal transmission mechanism. Such a supporting wall structure in the prior art is known in which, for example, a supporting wall member is mounted on an inner peripheral wall of a transmission case (see, "A Primer of Automatic Transmission", on page 199, FIG. 8-20, published by GURANPURI, Ltd., on Jun. 5, 1995).
In assembling such a prior art toroidal type definitely variable automatic transmission, after placing a toroidal transmission mechanism and then, the supporting wall member within a transmission case, constituting parts of a forward and backward change-over mechanism and parts of an oil pump and the like are assembled one by one in a main line. So there is a drawback that the line assembly efficiency is degraded due to lack of subassembling.